FIG. 1 is a perspective view of a packing box;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and

FIG. 7 is a bottom view thereof; and,

FIG. 8 is an enlarged detail view of the lower side of FIG. 2.

The portion shown by broken lines is for illustrative purposes only and forms no part of the claimed design.